Vacuum heating system



-v 1940- J. LAVERGNE 2,186,680

VACUUM BEA-TING SYSTEM I Filed May2, 1936 5 sheets-sheet 1 FlTToRNcY- Jam 1940- J. LAVERGNE VACUUM HEATING SYQS'IEM 5 Shets-Sheet 2 Filed May 2, 1936 av S IINV E H-roR: TERM Lava-mama BFOZ/MMM FITTORNEW Jan. 9, 1940. J. LAVERGNE' 4 0 "VACUUM HEATING SYSTEM Filed May'2, 1956 -5 Sheets-Sheet s nuv a N-rom U'Erm LfivcReN:

FITToRNzY Jan. 9, 1940. LAyERGNE- 2,186,680

VACUUM HEATING SYSTEM Filed May 2, 1956 I 5 Sheets-Sheet 4 INVENT'OH'. Ten: LHVERGNE Fwd-OR N :1-

Jan. 9, 1940. Y J. LAVERGNE 2, 5, VACUUM HEATING SYSTEM Y Filed May 2', 1936 5 Sheets-Sheet 5 .JE ZAZ Patented Jan. 9, 1940 UNITED STATES PATENT OFFICE 2,186,680 VACUUM nna'rme' SYSTEM .llean 'Lavergne, Paris, France,

assignor to Autocalor", Socit Anonyme, Paris, France, a body corporate of France Application-May 2, 1936, Serial No. 77,468 In Belgium May 21, 1935 7 Claims.

My invention relates to systems of heating by Two forms of essential construction of .this' heating system are known:

1. The fixed vacuum system in which steam at constant temperature is employed.

2. The variable vacuum system in which steam at variable temperature is employed.

In the system mentioned under (1), a relief valve is provided on the departure pipe-line which valve is adjusted for a pressure lower than that of the atmosphere, and in order for the relief valve to open and allow steam to pass it is necessary for a pump to produce in. the heating network a vacuum corresponding to the regulating pressure of the expansion device.

The fixed vacuum may be regulated for any pressure. It may be carried out with any steam temperatures between 55 and 100 C.', but the temperature fixed by the original regulation cannot be varied.

When it isa matter of buildings with regular heating during the whole of a winter, it will be seen that the'fixity of the temperature of the steam does not enable one to obtain an advantageous adjustment corresponding to the variations of the external temperature and permitting comfort and maximum fuel economy to be secured.

That is why installations have been constructed which operate under variable vacuum and distribute the steam at a variable temperature to the radiators.

In these systems operating with variable steam temperature the pipe-line carries variable quantities of steam at different densities due to the variations of temperature. The work of the vacuum pump consists in ensuring the circulation of this steam while maintaining in the entire network the necessary vacuum for obtaining the desired steam temperature.

In a network of pipe-lines of vacuum heating, two very distinct portions can be distinguished:

1. The pipe-lines conducting the steam to the heating appliances.

2. The pipe-dines which return the condensed water to the boilers, and as these two portions are separated by radiators, it will be appreciated that the steam leaving the principal header of the boiler to pass to the radiators is subject to a loss of head which is variable according to the absolute pressure prevailing in the network,- which absolute pressure determines the quantity 5 of steam to be transported into the heating appliance.

The object of this invention is to produce automatically a vacuum corresponding to the quantity of steam necessary for the heating network, this 1 quantity of expanded steam being always proportional to the temperature prevailing in the rooms to be heated. I

With a view to accomplishing this object, the invention comprises substantially the utilisation of a vacuum and steam relief valve or a combustion regulator composed of flexible diaphragms fixed to a system of levers and counterweights moving simultaneously so as to maintain difierences of pressure proportional to the resistances 20' It should be remarked, however, that in such a 80 system it is indispensable that the vacuum produced does not exceed the losses in head to be overcome for ensuring the movement of this steam.

In fact, if the partial vacuum produced is 35 greater than the losses .of head the excess work ofxthe pump evaporates the water in contact with the saturated steam.

\ In this case, the vacuum pump functions without stoppages to produce steam from the critical. 40 point at which the partial vacuum has exceeded the work necessary for overcoming the losses of head. It follows from this fact that the fall in vacuum is impossible.

It will thus be understood that it is important 45 to have an automatic regulation such that there corresponds to each quantity of steam sent into the network:

1. The vacuum necessary for obtaining steam adapted to ensure without excess the temperature of the rooms.

2. The difference in vacuum necessary, and without excess, for overcoming at any instant the sum of the losses in head.

The resistances which have to betaken into consideration are the following:

1. The loss in head during flow in the pipe-line from the regulator to the cock of the radiator (RI).

'2. The resistance to the passage of the steam through the cock (R2) 3. The resistance to the passage of the conden-, sation water through the drain-cock (R3).

When an installation is completed the invariable resistances are.the losses in the lines (RI) and those of the drain-cock (R3) adjusted at the works. The magnitude of the losses (RI) may .vary appreciably from one circuit to the other in view of the material impossibility of ensuring losses of head which are equal in all the circuits.

According to the invention, in order to regularise the whole and to obtain an exact equal distribution of the pressures the resistances R2 are modified according to requirements so that the sum of the resistances RI+R2 is quite constant for all the circuits.

Steam heating systems are known in which a difierential pressure controller is connected between the supply and return sides of the system, the controller governing the operation of the exhausting means so as to maintain a substantially constant and predetermined diiference in pressure between the supply and exhaust sides of the radiator, irrespective of the absolute steam pressure in the radiator. In this system, a pressure reducing device is automatically controlled by an electric device actuated by a thermostat situated in one. of the rooms being heated. Changes in the temperature of the room give rise through the pressure reducing valve to variations in the supply, the pressure and the temperature of the steam.

A vacuum controller produces the regulation by maintaining a constant difference of pressure between the vacuum produced by the pump and the absolute pressure obtained at the pressure reducing valve under the action of the thermostat.

The automatic pressure reducing device and the vacuum controller can only work correctly if each radiator is provided'at its outlet with a thermostatic steam trap which allows the exhaust of the condensate in the return pipe only when the condensate is at a temperature which is lower than the vaporizing temperature corresponding to the pressure of the vacuum produced by the pump.

As soon as the steam reaches the thermostatic diaphragm of the trap, the latter expands and ohturates the passage through which the steam escapes in the condensed form (i. e., as water). As the water does not escape into the return line,

it accumulates around the diaphragm and in the radiator. When the temperature of the water has been lowered sufliciently, the diaphragm contracts and permits the flow of the condensate. when steam is again received on the diaphragm, the

latter expands and the passage again closes.

In this system it has been suggested to provide change in the difl'erential pressure between the supply and return sides of the space exhausted by the particular element.

In those known systems, there exists a vacuumreservoir 5 for the condensed water.

diflerence which is constant whatever may be the pressure and the temperature of the steam. The consequence is that an increasing supply of steam is obtained, when the temperature falls. In the present invention, on the contrary, the controller acts in such a manner that the difierence of pressure is always proportional to the resistances to be overcome so that the vacuum diilerence diminishes when the quantity of steam diminishes and there exists no steam in excess.

The invention likewise relates to a construction of cocks intended to be utilised in the heating system (according to the invention) and rendering possible the adjustment of the said resistance R2, and also to a type of drain-cock adapted for use in this system.

The accompanying drawings show how the invention may be carried into practice:

Figure 1 shows a general diagram of a heating installation according to the invention;

Figure 2 is a sectional view of an expansion device for regulating the vacuum and the temperature of ,the rooms;

Figure 3 shows an installation in which a regulator is employed for the vacuum, the combustion and the temperature of the rooms;

Figure 4 shows a cock adapted to be placed on a radiator employed in a heating system 'according to the invention and oi. the type of that shown in Figure 5;

Figures 6, '7 and 8 are detail views;

Figure 9 shows a type of drain-cock to be fixed on a radiator of the type shown in Figure 5;

Figure 10 shows a cock which is provided with an air-escape device and intended for radiators fed by a single pipe conducting the steam and returning the water as shown in Figure 11;

Figure 12 is a view in detail;

Fig. 13 is a 'rear view of the vapor tension thermometer.

Referring to the drawings (Figures 1 to 3), i denotes the boiler and 2 the principal steammaniiold and 3 is a secondary distribution manitold to which are connected conduits Ci-CZ- C3 cl, c2, 03, etc terminating at the heating apparatus, for example radiators 4. Leaving the heating apparatus 4 are return conduits R, TI, r2, 13, etc. which terminate at a 6 denotes the drain-cocks and I the cocks of the radiators, 8 a syphon drain and 9 a general air vent.

On the conduit 3, is a pressure reducing apparatus for regulating the vacum and the temperature of the room, which apparatus is denoted by A in Figure 1 and is shown in a detailed manner in Figure 2.

This apparatus comprises in the first p ace a chest III which is fixed to the manifold 3 and which comprises in the lower portion a diaphragm ll clamped between a flange I! on the said chest and a lid l3. Fixed to this diaphragm II is a rod II to which is connected .a valve l5 controlling the passage of the steam. But even when the said passage is closed there remains an orifice it which allows a certain fiow of steam depending upon the magnitude of the installation.

The device also comprises two orifices 60 and GI oi equal dimensions and adapted to be closed by pistons! and 63- assembled by a system of fins 64 for guiding. The whole is mounted on the rod ll- In the'solid line position, the pistons 62, 63 close the orifices ill and GI. Underthe influence of the action of the pressure on the diaphragm, the pistons move vertically and finally occupy fold 3 serves to support a chest I8 formed in two parts which clamp between them a diaphragm I9. The space situated above the said diaphragm is connected by a pipe .2| to a vacuum pump 22 which likewise exerts its action in all the pipe-lines through the medium of a conduit 23 connected to the reservoir 5 and provided with an indicator 24 for the vacuum and temperature.

Fixed to the diaphragm II of the relief valve is a link 25 which is connected to a lever 26 adapted to oscillate about a pin 21 fixed to a lug 28 on the lid I3 and which lever 26 is pro-- vided with a slot 29 in which is a pin 3|! supporting a weight 3|. The pin of the weight is connected by a rod 39 to the lever 48 which is adapted to oscillate about a pin 4| and which can 'gctuate simultaneously the counterweights 3| and A similar arrangement is provided for the vacuum-regulating diaphragm, to which is fixed a link 32 which is connected to a lever 33 which pivots about a pin 34 fixed to a lug 35 and comprises a slot 36 provided with a pin 31 for the suspension of a weight 38. The pin of the weight is connected by a link 41 to an arm of. the lever 48 just referred to which is adapted to pivot about a pin 4|. The said lever is provided with an extension 42 adapted to be fixed in predetermined positions by a pin entering the holes 43 .of a sector 44. The arm 48 is provided with a counter weight 46 at the end of its base 45.

Fixed to the lever 33 is a rod '48 acting on the electrioocircuit of a circuit-breaker 49 of known type adapted to stop the motor of the pump 22.

The operation is as follows:

The system being cold and the heating boiler not lit, if the pump 22 is'put into operation, vacuum is produced in the whole of the heating network, both in the return pipe-lines and in the steam pipe-lines.

The vacuum pump '22 exerts its action on the diaphragm I9 through'pipe 2| and on the dia-- phragm I I through the'pipe 23, reservoir 5 and the return pipes. When the vacuum attains the necessary intensity for balancing the weight 38, the lever 33 is raised and by means of the rod 48 breaks the electric circuit of the circuitbreaker 49 which stops the motor of the pump. Furthermore, the diaphragm II of the reducing v valve is likewise raised under the influence of the vacuum, and keeps open the balanced valve system which has to give passage to the steam.

As will be understood, by operating the lever 48 it is possible to move the weights 3| and 38, the controls of which are connected together, by virtue of the-two links 39 and 41, and it is possible to increase or diminish the vacuum at will.

v When the system operates under vacuum by the working of the pump but without steam being sent into the plant, so that the vacuum extends in a regular manner and with constant absolute pressure in the plant, the pressures are equal at the vacuum regulator and at the reducing valve.

Considering now the normal operation, the steam from the boiler I passes through the fixed orifice I8 and the balance valve I5 of the reducing valve expands under. the influence of the vacuum and fills the entire steam network. Its absolute pressure is exerted on the diaphragm II and due to its action the quantity of steam passing thereiief-valve is proportional to the intensity of the vacuum prevailing in the system.

The systems of levers and counterweights 29- 3| and 33-38 are designed so that the difference in the absolute pressures prevailing on the diaphragms II and I9 is always equal to the losses in head caused by the steam in the distribution pipe-lines, together with the resistances of the cooks and drain cocks of the radiators, as will herein after be more fully explained.

For that purpose the path through which each counterweight travels with respect to the path of the other counterweight varies in proportion to the drop in vacuum. The difference at the commencement of the movement, when the steam temperature is highest is greater than at the end when the temperatureis lowest.

The following example shows in detail the oper-- ation of this partof the apparatus.

The lever 40 being pivoted at 4| can act as explained on the weights 3| and 38.

If it is remembered that the paths of the weights 3| and 38 are different, when the lever 40 is displaced, as the pivoting points 65 and 66 are situated at distances which are different from the pivoting point 4|, it will be obvious that the paths followed by the weights 3| and 38 are quite different. If the centreBG is displaced, either by putting it closer or farther from the centre 4|, it is possible to vary the ratio of the paths followed by the weights.

During the movement of the lever 40 the pivoting points 65 and 66 cause the weights 3| and 38 to travel through different parts corresponding to their distance from the centre 4|. moved by weight 38 is less than that moved by weight 3|; .Moreover, as the weights progress toward the right the effective force of weight 38 on its lever 36 is less and less than that of weight 3| on its lever 26.

At the start, the weight 3| is slightly to the left of the pin 21 .and the weight 38 to the right of the pin 34.

There is produced a difference in pressure exerted by the weights on the diaphragms. This difference corresponds to the loss in head produced by the circulation of the steam at its highest temperature, that is to say, about 100 C. It is to be noted, however, that weight 3| does not exert a pressure on diaphragm II when said weight is at the left of the pin 21. 4

When the weights 3| and 38 are at the opposite end, this differencein initial pressure is reduced appreciably in order tomake it correspond to ondly the ratio of this difference in the initial pressure when the temperature of the steam is highest to the final difference corresponding to the lowest temperature.

In all the successive positions occupied by the weights 3| and 38 these differences are always In other words, the entire distanceg the new loss in head produced by the steam at proportional to the losses in head due to the flow of steam for the flows corresponding to the steam temperatures in the limits of about 60 C. and

Under the influence of the action of the vacuum pump, the weight 38 is gradually raised and the pivot of the rod controlling the circuit-breaker is thus caused to occupy successively positions which eventually cause the interruption of the electric circuit and the stopping of the motor of the pump. The inverse phenomenon is produced when the vacuum has become insuflicient. As the weight 38 rises; due to the flxity of the centre 65, it also approaches the pin 34 which diminishes its action and facilitates the rapid control of the circuit-breaker.

When the vacuum is weak and the steam is at its highest temperature, the weight of steam carried is a maximum, and the differences in the absolute pressures on the diaphragms II and I! are also a maximum. Conversely, when the vacuum is high and the temperature of the steam is low, the weight of steam carried is a minimum and the difierences in the absolute pressures on the diaphragms H and i9 are also a minimum.

When the vacuum is low at the exit of-the steam from the steam pressure reducing apparatus for instance with an absolute pressure of 0.950 kgr. the weight of steam which is carried may be supposed to be of 2000 kgr. per hour. The differences in the absolute pressures on the diaphragms II and I9 are-also a maximum and can be regulated to a difierence of 0.150 kgr. When the degree of vacuum is important and the corresponding absolute pressure is of 0.200 kgr., the weight of steam which is carried can be regulated by means of the apparatus within the limits of 400 to 800 kgr. perhour.

This combination of levers is therefore such that in all points of the position of the weights 3| and 38 along the levers, the differences in absolute pressures on the diaphragms II and I9 correspond exactly to the losses in head due to the flow of steam in the distribution network.

When this difference exceeds by a very small quantity the said loss of head, the lever 33 is raised and by means of the rod 48 breaks the electric circuit of the circuit-breaker 49 and Stops the motor of the pump; when the vacuum diminishes and the difierence in absolute pressure on the diaphragms H and I9 is a little less than that necessary, the weight 38 actuates the lever 33 and by means of the rod 48 starts up the motor again for the time necessary to re-establish the required difierence. V

In order to effect the regulation of the temperature of the rooms, the pressure of the water from a reservoir 50 (Figure 1) is utilised, which water may be carried by a pipe 5| to a chest 52 containing a diaphragm 53 on which the water acts. The water of the pipe-line 5| (Figure 2) comingfrom the reservoir passes through a capillary diaphragm 54, exerts its pressure on the diaphragm 53, leaves by a tube 55, passes through a thermometer dial and returns through the conduit 51 to the pump reservoir 22.

To summarize, the plant is composed of the following main elements:

I. The temperature regulating device.

II. The vacuum regulating device.

III. The steam expansion regulating device.

The temperature regulating device is composed of a casing containing the diaphragm, 53. To one The vacuum regulating device One face of the diaphragm l9 actuates, through the intermediary of link 32 the system of levers 33-36 adapted to oscillate around a fixed point 34.

The other face of the diaphragm is in communication through the pipe 2| with the vacuumpump and the return pipe of the plant.

The system of levers 33-36 includes the weight 38 which is adapted to be displaced along the entire length of the branch 35 of lever 33.

If the surface of the diaphragm is equal to Sn cm and if the weight 38 suspended at the centre of the diaphragm is of P kgr. the diaphragm begins to be tilted progressively when the vacuum pump has produced a depression equal to When the degree of vacuum has become slightly greater than and when it has reached a quantity of the rod 48 will stop the motor by means of the circuit breaker 49. When the vacuum has diminished by E, the system of levers begins a movement in a reverse direction before it reaches an equilibrium state of When the degree of vacuum-has diminished by still another quantity E, the rod 48 will again put the motor into operation.

There will consequently exist, a permanent vacuum comprised between:

In the expansion regulating device oneof the faces of the diaphragm actuates a system of levers adapted to oscillate about a pivot 21. The other face of the diaphragm is in communication with -the steam pipe and actuates a system of valves 62-63 the object of whichis to control the expansionof the steam coming from pipe A and entering the feeding pipeB of the plant.

The weight 3| is adapted to be displaced along the lever 26.

If the system is equilibrated and if the pressure at B is of one atmosphere, the difference between the pressure on the diaphragm II and the pres- 'sure on the depression produced by the vacuum pump in the vacuum regulating device will be equal to 5 S, If p=12 kgr. and if Sn=80 cm.

LLB: 2 0.150 kgr.1500 kgr./M

.This is the working pressure corresponding to a temperature of 100 C.

The thermometer dial is of any known type.

It is constituted by a saturated vapour tension thermometer. The. liquid of this thermometer may be methyl-chloride and is contained in a reservoir 58. This reservoir is placed in the room the temperature of which is to be maintained constant. The reservoir is connected to a thin tube o which enters the apparatus at a (Fig. 13) and is curved around behind the thermometer dial, the free end of the tube being connected with a tank d containing a system of metallic tubes of a well known type to which is fixed a rod h. This rod controls a lever I under the influence of the vapor tension. At the extremity of lever Z is suspended an equilibrated piston p which, under the influence of the movement produced by the vapor tension obturates more or less the passage for the liquid under pressure which enters the apparatus through-a tube r and is discharged therefrom through a tube q. The pivotal center s of lever I may be manually displaced in order to obtain the desired regulation of the fixed temperature. The

tube opens or closesunder the influence of the variations in temperature of the room and by its movement opens or closes a small capillary-orifice valve placed in the pipe-line. The opening or closing of this small valve impedes more or less the outlet of .the liquid and thereby causes a variation in the pressure on the diaphragm 53.

This variation in the pressure actuates a lever 59 which is fixed to the diaphragm 53 and which controls by means of the lever 40 the movement of the counterweights 3| and 38 so that a temperature. of the steam corresponds to a given temperature of the room.

When the system is inoperative and the room is cold, the small valve is closed and all the pressure of the reservoir is exerted on the diaphragm 53, thereby moving the weights towards the pivoting points of the levers. At this point the vacuum is weak and when the system is operative, the steam has a temperature in the vicinity oi. 100 C.

When the desired temperature in the room is attained, the valve opens and allowsthe water to flow gradually, thereby diminishing the pressure on the diaphragm 53, and the weights 3| and 38 actuated by the balancing counterweight 48 move towards the end of the levers- 26 and 33, thereby producing an increase in the vacuum and a diminution in the temperature of the steam. The weights 3| and 38 are fixed in a position corresponding to the temperature desired in the room, which temperature may be varied at will by operating a button 68' (Fig. 2) which moves the needle of the dial to the desired temperature.

It will be remarked that the system may also operate by dispensing with the automatic regulation of the temperature. In this case the operation is effected manually and the lever 88', extended beyond its pivoting point, may be fixed in all the desired positions as explained hereinbefore. d

The system of relief-valve and regulator for the vacuum and forthe temperature of the room which has just been described is applicable above all to large installations in which the action of tion chamber.

the vacuum doesnot extend to the boilers. The steam produced in the latter at any desired pressure is expanded into the vacuum for its utilisation.

In this case the vacuum pump while maintain- 8 ing the absolute pressure necessary in the heating network, ensures the feeding of the boilers with. condensed water.

In smaller installations, the vacuum producedv by the pump extends to the boilers which are generally fed with condensed water directly by gravity.

, In this case, the steam not being expanded the regulating system acts directlyon the combustion for proportioning the quantity of steam necessary for heating.

The apparatus shown in Figure 3 comprises the same references as that shown in Figure 2 (I8 denoting an overflow pipe).

The relief-valve is replaced by a, lever 61 pivoting on its centre 88. This lever is controlled by a rod 69 pivoted to the end of the slotted lever 28.

To the opposite ends of the lever 61 are secured flexible cables I8 and 1 I, passing respectively over guide pulleys I2 and 13, the cable 10 being secured at its free end to the damper door disposed in the chimney and adapted to control the draught, while the free end of cable II is secured to the door 14 below the fire-box for controlling the admission of air for combustion. It will thus be seen that as the lever 61 swings on its pivot in one direction, the door 64 is lifted from its closed position while the door 15 gravitates toward its closing position, thereby increasing the draught through the combustion chamber, and when the lever swings in the opposite direction, the said doors I4 and 15 will also be operated in the direction opposite from that above described thereby reducing the draft through the combus- The combustion is thus synchronised with the vacuum regulator in the same way and in the same conditions as in the apparatus already described in Figure 2. v

In many ,cases the regulator for the temperature of the rooms is dispensed with. The control of the regulation of the-temperature of the steam is efiected directly by hand, the lever 48 being fixed in the desired position for obtaining that temperature.

As already stated, the cocks or valves and draincocks utilised in the system according to the invention have special features which are directly related with the system according to the invention. i

The cook or valve shown in Figure 4 comprises a body 16, a connecting piece 11 by which it-is fixed to the radiator and'a head 18 which is fixed to the body 16 by a screwthread 19.

The head 18 which is readily accessible comprises a rod 80 of small diameter carrying in its extension a part 8| of greater diameter.

These two cylindrical parts are connected together by a conical part 82 carefully ground to the head 18 in an appropriate recess.

The rod 88 extended to the outside is provided with a handle 83 or operating hand-wheel permanently fixed to the rod, or a notched system 84 (Figure 6) intended to be operated by a detachable handle or key 88 (Figure '7).

A spring 88 placed in a cylindrical recess of the head 18 exerts its pressure between the operating handle or ring fixed to the rod and the bottom of the cylindrical recessof the headso that. under the influence or this pressure, the around i surfaces of the conical part of the rod are always in good intimate contact. Y

Within the interior of the cylindrical part II, an appropriate screwthread receives a needle 81 shown separately in Flgure8.

This needle comprises in a single block a first cylindrical part A of dimensions variable according to the resistance of passage to be obtained, a second part B of square section and the part 0 screwthreaded in accordance with the internal screwthreads of the cylinder 8l..

The parts A and B of the needle valve 81 are connected by a cylindrical partD forming the seat of the valve.

The unit formed by the cylinder 8| and the needle 81 is placed in the interior of a part 88 permanently-screwed on the head 18 and having an internal form appropriate for housing the cylinder 8| and the square part of the needle and cylindrical part of the seat.

It will be readily appreciated that operation of the handle 83 or 85 to impart rotation to the rod 80 moves the needle for opening or closing the valve and by this simple operation increases or diminishes the quantity of steam admitted into the radiator. I

when the valve is entirely opened and it is desired to adjust the installation for limiting the flow of steam and producing the useful resistance it is merely necessary to employ a needle valve, the diameter A of which is more or less considerable.

Due to this fact, when the adjustment of an installation is concluded and the heads 18 have been well-locked, the system absolutely cannot get out of order.

The ground conical joint device ensures permanent fluid-tightness of the system without limitation' of its lite and without any upkeep.

In these conditions, taking into consideration that the line resistance and the local resistances can never be established in a very exact manner, it will be understood that there can exist differences from one circuit to another,-which makes it necessary to'have an adjustable resistance, more particularly the valve, whereby it is possible to have a total resistance equal for each circuit.

As will be understood, the valve described is constructed so that it is easy to cause this resistance to vary more or less, so that the adjusting device once fixed can only be altered by a special workman having the necessary tools for doing this work.

Figure 9 shows the drain-cock for the condensed water, which ensures the resistance R8 and forms an insurmountable obstacle to the pas-V sage of the steam.

It comprises a body 88 provided with two connecting pieces 80 and 8| for the inlet and outlet of the condensed water.

The body 88 forms a steam cut-off device which always contains a certain quantity of water.

In each branch of this siphon is immersed a cylindrical rod 82 provided in its lower portion with a certain number of circular fins 88, in the example shown seven, forming six successive expansion chambers 84 The connecting pieces are made of a very definite diameter,.i. e., of a diameter which depends on the quantity of water which to the passage in the chamber formed by two consecutive fins.

One of the connecting pieces, as for instance the piece 80, of the siphon is connected to a reservoir oI-water under a head, the level of the water being maintained 200 mm. above the axis of the said connecting piece. It is only necessary to measure the water which flows freely through the other connecting piece, care being taken to maintalnthe level of the water of the reservoir constant at 200 mm., to determine the drainage capacity of the apparatus, since the quantity of water which flows this head of 200 mm; represents such drainage capacity.

For example, a radiator giving 21,000 calories at 100 C. should discharge per second If the dimension of the fins is designed to only allow this quantity to pass per second, the apparatus may be mounted on a radiator of 21,000 calories. In other words, the draining devices have for their object to furnish a certain quantity of water under a given pressure. Generally, the apparatus is designed to furnish that quantity of water under a load corresponding to a height of 20 cm. of water, i. e., 20 gr. The draining device is consequently calibrated so as to permit its working with that load. But to vary the output, it is necessary to modify the space separating the external diameter 'of the fins from the diameter of the chamber in which they are located.

The apparatus thus adjusted will give a resistance of 200 kilograms at 21,000 calories.

At 60 C., the discharge will only be 6,000 m-SJIS cubic millimetres =l0,903 cubic millimetres and the resistance to flow will have 73 kilograms as a maximum in order to follow the variations in the losses in head RI+R2+R3.

Since, however, actually the resistance to the flow of the water alone is only 16 kilograms, the first fins oi the branch of the siphon are immersed in the steam or expanded air to the level at which the resistance of passage has increased by 57 kilogram which added to 16 gives the '73 kilograms of useful resistance.

The foregoingflgures are only given to explain concretely the operation 01' the drain-cock or steam trap but instead of 200 kilograms of resistance at the start, any other greater or smaller value may be employed without modifying the result, except that in this case merely the diameter of the fins would be greater or smaller.

A feature of this type of steam trap is that if the steam under the influence of asudden pressure drives out the air and fills the apparatus, it

is stopped at the end of the third or fourth fin and an eflective pressure of 5000 kilograms does not allow it to reach the bottom of the siphon. In other words, when the'draining device has been calibrated for a well determined output .0! water,

for instance 12 kgr. in one hour, even ii. the draining device furnishes only 500 gr. 0! water instead of 12 kgr., the said steam will not pass even under a pressure which is more than 20 times the normal pressure.

This drain-cock or steam trap which ensures under a very low pressure a regular discharge of the air and water forms an insurmountable obstacle to the passage of the steam.

The drain-cock thus constructed is sumcient to separate the radiators from the return line.

Figure 10 shows a valve of the type shown in Figure 4 and constituting a combined valve and steam trap.

It is intended to be used on radiators fed with a single pipe as shown in Figure 11. It is fixed on a one side at a certain height of the radiator and on the other it is connected to a special air pipeline leading to the vacuum pump (at 95).

Between the valve and the vacuum line is inserted a fin-resistance shown in" Figure 12.

This resistance which is introduced into the valve through the plug 96 is provided on each end with a blind hole 91 and a second hole 98 perpendicular to the latter and opening into the first chamber.

The detachable needle of this valve is of fixed dimensions and cannot be altered, the resistance which is opposed to the passage of the air being indifierent. to the normal-operation of the system.

The object of this valve is, when it is closed, to prevent the radiator from being cleared of the air which it contains and due tothat fact, the heating apparatus which cannot be fed with steam, remains constantly cold. When it is opened,'the steam takes the place of the air discharged by the pump.

comprising a chest having a flexible diaphragm" When the steam reaches the valves and arrives at the fin-resistance, the latter opposes an insurmountable obstruction to its passage, irrespective of the difference of absolute pressure between the interior of the radiator and the vacuum line.

- The steam which passes the first fins forms in fact a stopper for the steam which comes afterwards.

If during the operation of the radiator the valve is closed, the heating apparatus is progressively cooled and after a certain lapse of time which varies with the heating surface becomes completely cold.

Nevertheless, it is important to point out that during the operation of the radiator, the air which is discharged automatically is saturated with water vapour which condenses in the interior of the vacuum line. This quantity is, however, negligible. In the case of the valve according to Figure 10, therefore, the steam trap device merely serves to discharge air and has no function con-.

cerning the discharge of the water.

.I claim:

1. A vacuum heating system comprising in combination, a steam producing apparatus including a manifold and a distribution system and return conduits, a vacuum producing device in communication with the entire distribution system, a vacuum regulator including a chest secured to said manifold and containing a flexible diaphragm, the space in said chest at one side of said diaphragm being in communication with the vacuum producing means whereby the diaphragm will be actuated in-response to variations in the degree of vacuum, a steam expansion regulator exposed at one side thereof to the steam supply at the outlet of the expansion regulator, pivoted levers connected respectively to said diaphragms in such manner as to weight the diapnragmson the side thereof opposite to the side in communication with the vacuum producing means and the steam supply respectively, counterweights carried by said levers and slidable thereon to vary the' weight, and thermostatic means for actuating last means. H

2. A vacuum heating system comprising in com bination, a steam producing apparatus including a manifold and a distribution system and return conduits, a vacuum producing device in communication with the entire distribution system, a vacuum regulator including a chest secured to said manifold and containing a flexible dia-v phragm, the space in said-chest at one side of said diaphragm being in communication with the weights simultaneously but at difierent rates whereby the difference in absolute pressuresv on the diaphragms corresponds to the losses in head due to the flow of steam in-the distribution system, and thermostatic means for actuating said interconnecting means "in response to variations in temperature. I

3. A vacuum heating system comprising in combination, a steam-supplying systemincluding distribution pipes and return conduits, vacuum-producing means in communication with said system. vacuum regulating means and steam-expansion regulating means in communication respectively with the vacuum-producing means and steam-supplying system, pivoted levers connected respectively to said vacuum and steam-expansion regulating means, weights slidable on said levers for varying the leverage thereof, meansv interconnecting said weights for moving them simultaneously but at difierent rates thereby to progressively bias said regulating means, and thermostatic means automatically operative to actuate said interconnecting means thereby to maintain differences of pressure proportional to the heating eifect produced by said steam-supplying system.

4. A vacuum heating system comprising in combination, a steam-supplying system including distribution pipes and return conduits, vacuum-producing means in communication with said system, a vacuum regulator and a steam-expansion regulator, each of said regulators including a flexible diaphragm in communication respectively with the vacuum-producing means and the steam-supplying system, means actuated by said diaphragms for controlling the vacuum production and steam expansion, pivotedlevers connected respectively with said diaphragms for weighting them at the sides thereof opposite to the sidesin comunication with the vacuum producing means and the steam supply respectively,

means movable on said levers for varying the leverage thereof, means interconnecting said movable means for moving them simultaneously but at different rates thereby to progressively bias said regulating means, and thermostatic means for actuating said interconnecting means thereby to maintain differences of pressure proportional to the heating effect produced by said steani-supplying system.

5. A vacuum heating system comprising in combination, a steam-supplying system including distribution pipes and return conduits, vacuum-prophragms at the sides thereof opposite to the sides in communication with the vacuum producing means and steam supply respectively, each of said levers having an elongated slot extending longitudinally thereof and a counterweight suspended from said slot and movable lromend to end thereof, means interconnecting said weights for moving them simultaneously but at different rates along their respective slots thereby to vary the leverage and progressively bias said regulators to maintain difierences of pressures proportional to the heating eflect produced by said steam-supplying system, and adjustable thermostatic means automatically operative to control the action of said interconnecting means.

6. A vacuum heating system comprising in combination, a steam-supplying system including distribution pipes and return conduits, vacuum-pro-.

ducing means in communication with said system, a vacuum regulator and a steam-expansion regulator, each of said regulators including a flexible diaphragm in communication respectively with the vacuum-producing means and the steam-' supplying system, means actuated by said diaphragms for controlling the vacuum production and steam expansion, a pivoted lever connected to each of said diaphragms for weighting the dia-' phragms at the sides thereof opposite to the sides in communication with vacuum producing means and steam supply respectively, each of said levers having an elongated slot extending longitudinally thereof and a counterweight suspended from said slot and movable from end to end thereof, pivoted levers interconnecting said weights for moving them simultaneously but at difierent rates along their respective slots thereby to vary the leverage of said slotted levers and the consequent weighting of their associated diaphragms, a third flexible diaphragm connected with said interconnecting levers for oscillating the same, means for normally maintaining said third diaphragm at a predetermined position, and thermostatic means effective to control said diaphragm-maintaining means.

'l. A vacuum heating system comprising in combination, a steam-supplying system including distribution pipes and return conduits, vacuum-producing means in communication with said system, a vacuum regulator and a steam-expansion .to each of said diaphragms for weighting the diaphragms at the sides thereof opposite to the sides in communication with the vacuum producing means and steam supply respectively, each of said levers having an elongated slot extending longitudinally thereof and a counterweight suspended irom said slot and movable from end to 1 end thereof, pivoted levers interconnecting said weights for moving them simultaneously but at different rates along their respective slots thereby to vary the leverage of said slotted levers and the consequent weighting of their associated dia-- phragms, a third flexible diaphragm connected with said interconnecting levers for oscillating the same, means for supplyingliquid pressure to said third diaphragm thereby to set the same to maintain said interconnecting levers at a predetermined position, and means for reducing said liquid pressure. 

